The lipid paradox is also present in early axial spondyloarthritis: results from the Swedish part of the SPondyloArthritis Caught Early (SPACE) cohort.

OBJECTIVE: Inverse associations between systemic inflammation and cholesterol ('the lipid paradox') have been reported in rheumatoid arthritis (RA) and, in established axial spondyloarthritis (axSpA), but little is known about this relationship in early axSpA, which is the focus of the present study. METHOD: In the Swedish part of the SPondyloArthritis Caught Early (SPACE) cohort (patients with chronic back pain for ≥3 months, ≤2 years; age at onset <45 years), serum levels of total cholesterol (TC) and apolipoproteins ApoA1 and ApoB were measured at inclusion, together with parameters reflecting inflammatory disease activity [C-reactive protein (CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and sacroiliitis by magnetic resonance imaging (MRI) following Assessment of SpondyloArthritis international Society (ASAS) criteria]. All patients included in the analysis either had axSpA based on a high physician's level of confidence or fulfilled the ASAS criteria for axSpA. Associations between lipids/lipoproteins and inflammation were assessed using multivariable linear regression models. RESULTS: In the 64 patients included, there were inverse associations for CRP with TC, ApoA1, and ApoB in age-sex-adjusted models. The negative associations with CRP remained significant for TC and ApoB in multivariable models adjusted for age, sex, BASDAI, and current smoking (p = 0.048). There were no significant associations for the lipid parameters with BASDAI or inflammation on MRI of the sacroiliac joints. CONCLUSION: Inverse associations between systemic inflammation and lipids, particularly TC and ApoB, are present in early axSpA, similar to those shown for other inflammatory joint diseases. These patterns must be considered when including lipids in the evaluation of cardiovascular disease risk.

Health-related quality of life in gout, psoriatic arthritis, rheumatoid arthritis and ankylosing spondylitis, results from a cross-sectional survey in Western Sweden.

OBJECTIVES: Inflammatory joint diseases (IJDs) substantially affect health-related quality of life (HRQoL). We aimed to compare HRQoL between patients with gout, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and ankylosing spondylitis (AS): (i) overall; (ii) stratified by sex; and (iii) between women and men with the same IJD diagnosis. METHOD: A survey including the RAND36-Item Health Survey for assessing HRQoL was sent to patients with a diagnosis of gout, PsA, RA, or AS, registered at a rheumatology clinic or primary care centre during 2015-2017. HRQoL was compared across IJDs. Because of age differences between diagnoses, age-matched analyses were performed. RESULTS: In total, 2896/5130 (56.5%) individuals responded to the questionnaire. Of these, 868 had gout, 699 PsA, 742 RA, and 587 AS. Physical component summary (PCS) scores were more affected than mental component summary (MCS) scores for all diagnoses (PCS range: 39.7-41.2; MCS range: 43.7-48.9). Patients with gout reported better PCS scores than patients with PsA, RA, and AS, who reported similar scores in age-matched analysis. MCS scores were close to normative values for the general population and similar across IJDs. When comparing women and men with respective IJDs, women reported worse PCS (range, all IJDs: 34.5-37.4 vs 37.5-42.5) and MCS (PsA: 44.0 vs 46.8; RA: 46.1 vs 48.7) scores. CONCLUSION: We found that patients with gout reported better PCS scores than patients with other IJDs, for whom the results were similar. Women reported overall worse PCS and MCS scores than men.

Gout in Dalarna, Sweden - a population-based study of gout occurrence and compliance to treatment guidelines.

OBJECTIVE: This study aimed to describe the incidence and prevalence of gout, describe the use of allopurinol among prevalent gout cases, and determine persistence with allopurinol and degree of compliance with treat-to-target recommendations before and after the publication of Swedish national guidelines in 2016. METHOD: Prospectively registered data on gout diagnoses and allopurinol prescriptions were used to calculate incidence and prevalence, and the proportion of prevalent patients on allopurinol. Gout patients starting allopurinol during 2013-2015 versus 2016-2018 were compared regarding persistence and compliance with treat-to-target principles. RESULTS: The incidence of gout was 221-247 per 100 000 person-years during 2014-2019, prevalence in 2018 was 2.45%. Among prevalent cases, the proportion on allopurinol ranged from 21% to 25%. Allopurinol persistence was better for individuals starting therapy during 2016-2018 compared with 2013-2015 (45% vs 39%, p = 0.031), as were several outcomes related to treat-to-target principles, e.g. measuring baseline serum urate (SU) (84% vs 77%, p < 0.001), follow-up SU (50% vs 36%, p < 0.001), and the proportion of patients reaching an SU level < 360 µmol/L (45% vs 30%, p < 0.001). CONCLUSION: Incidence and prevalence were slightly higher than in previous Swedish reports. Allopurinol use among prevalent gout patients did not increase during 2014-2019. Only a minor improvement in persistence was seen, and a moderate increase in compliance with guidelines, suggesting a need for improved management and extended patient involvement to increase and optimize the use of urate lowering therapy.

Validity of clinical psoriatic arthritis diagnoses made by rheumatologists in the Swedish National Patient Register.

OBJECTIVES: : Knowledge of the correspondence between clinical ICD diagnoses and classification criteria fulfilment is crucial to interpret studies identifying cases via ICD codes. We assessed the degree to which patients registered with ICD-10 diagnoses of psoriatic arthritis (PsA) in the Swedish National Patient Register (NPR) fulfil established PsA classification criteria. METHOD: Four hundred patients with at least one outpatient visit to one of five rheumatology or internal medicine departments (three university/two county departments across Sweden) in 2013-2015, with a main ICD-10 diagnosis of PsA (L40.5, M07.0-M07.3), were randomly selected (80 cases/site). Through a structured medical record review, positive predictive values (PPVs) for fulfilment of the following classification criteria were assessed: CASPAR, Moll and Wright, Vasey and Espinoza, and modified ESSG criteria for PsA. A subset analysis regarding CASPAR fulfilment was also performed among cases with available rheumatoid factor and peripheral X-ray status (central CASPAR items; n = 227). RESULTS: Of the 400 patients with a main ICD-10 diagnosis of PsA, 343 (86%) fulfilled at least one of the four PsA classification criteria. PPVs for the different criteria were: CASPAR 69% (82% in the subset analysis), Moll and Wright 51%, Vasey and Espinoza 76%, and modified ESSG 64%. Overall, only 6.5% of the 400 PsA diagnoses were judged as clearly incorrect by the medical record reviewers. CONCLUSION: The validity of rheumatologist-made, clinical ICD-10 diagnoses for PsA in the Swedish NPR is good, with PPVs of 69-82% for CASPAR fulfilment and 86% for meeting any established PsA classification criteria.

Cardiovascular risk factors are highly overrepresented in Swedish patients with psoriatic arthritis compared with the general population.

Objectives: We aimed to determine the prevalence of cardiovascular risk factors in patients with psoriatic arthritis (PsA) followed at a large Swedish Rheumatology Clinic, and to compare differences in cardiovascular risk factors between men and women with PsA and with the general population.Method: A questionnaire was sent to patients with PsA registered at the Rheumatology Clinic at Sahlgrenska University Hospital, Gothenburg (n = 982). Comparisons with the general population were made using data from the Swedish National Public Health Survey. Descriptive statistics are presented. Body mass index (BMI) was calculated using self-reported height and weight.Results: Overall, 692 (70.6%) of the patients with PsA responded. The mean ± sd age was 55.6 ± 11.4 years and 52% were women. Obesity (BMI ≥ 30 kg/m2) was more prevalent (p < 0.001) in patients with PsA (28.6%) than in matched subjects from the general population (16.3%). Hypertension was also more prevalent (p < 0.001) in PsA (40.3%) than in matched subjects from the general population (24.1%), as was diabetes, with a prevalence of 10.5% in the PsA population compared with 6.2% in matched subjects (p < 0.001).Conclusion: We found obesity to be highly overrepresented in patients with PsA compared with matched subjects from the general population. This difference was particularly seen in women with PsA. Hypertension and ever smoking were also more prevalent in women with PsA compared with matched subjects from the general population.

Multiplex cytokine analyses in patients with rheumatoid arthritis require use of agents blocking heterophilic antibody activity.

OBJECTIVES: Heterophilic antibodies, such as rheumatoid factor (RF), are known to interfere with enzyme-linked immunosorbent assays (ELISAs). Treatment of rheumatoid arthritis (RA) with tumour necrosis factor (TNF)-α blockers is well established. The aims of this study were to develop a protocol for blocking the interaction of present heterophilic antibodies and to validate this procedure by evaluating the effect on correlations of cytokine levels to clinical response in RA patients treated with adalimumab. METHOD: Fourteen patients with active RA were evaluated at baseline and 3 months after starting adalimumab treatment. Cytokines were analysed with a commercial 12-plex bead ELISA. To block interference by RF, a commercial blocker (HeteroBlock) was used. To determine the optimal concentration of HeteroBlock, patient sera were analysed with different concentrations of HeteroBlock. Subsequently, baseline and follow-up sera from the 14 patients were analysed and correlated with clinical outcome. RESULTS: Measured cytokine levels were reduced in the majority of samples when adding the blocker. The optimal concentration of HeteroBlock was 1600 µg/mL of serum. Sera with high RF levels were more prone to produce false positive values, although some RF-negative sera also demonstrated evidence of interference. HeteroBlock did not interfere with the analysis. In RA patients treated with adalimumab, changes in interleukin (IL)-6 levels between baseline and follow-up correlated with changes in erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in sera with added HeteroBlock. CONCLUSIONS: When analysing sera from patients with RA with multiplex bead ELISA, the assay should be evaluated for interference by heterophilic antibodies, and if present corrected with, for example, HeteroBlock.